Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
  • B01D53/34—Chemical or biological purification of waste gases
  • B01D53/46—Removing components of defined structure
  • B01D53/64—Heavy metals or compounds thereof, e.g. mercury
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
  • B01D53/02—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols by adsorption, e.g. preparative gas chromatography
  • B01D53/06—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols by adsorption, e.g. preparative gas chromatography with moving adsorbents, e.g. rotating beds
  • B01D53/10—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols by adsorption, e.g. preparative gas chromatography with moving adsorbents, e.g. rotating beds with dispersed adsorbents
  • B01D53/12—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols by adsorption, e.g. preparative gas chromatography with moving adsorbents, e.g. rotating beds with dispersed adsorbents according to the "fluidised technique"

Definitions

• This invention relates to a method of purifying gas containing gaseous mercury according to the preamble of the attached claim 1.
• mercury also is emitted in flue gases, for example, from refuse incinerators. That emission part which is in particle state, can be separated by conventional dust separation technique. A great portion of the mercury emission, however, often is in the form of gaseous pollution which, besides, occurs in very low contents and, therefore, is difficult to separate.
• Known methods of separating mercury from gas mixtures are such, at which the gas mixture is caused to contact a liquid sorbent, or such, at which the mixture is caused to contact a solid sorbent.
• the present invention relates to the latter category. Examples of such known methods are disclosed in SE-PS No. 360 988, where the gas mixture is brought into contact with selenium or selenium compounds, or in U.S. Pat. No. 3,232,033 where the gas mixture is caused to contact metals having a strong tendency of forming amalgam, such as nickel, silver or gold.
• the method according to said Swedish patent is adapted for separating mercury, which occurs in high contents as, for example, at the manufacture of sulphuric acid.
• One disadvantage of the method is the very high price of selenium.
• the method according to said U.S. patent was developed for a process of manufacturing hydrogen gas, where the gas temperature is high and the mercury contents are high.
• the present invention has the object to render available a method, by which gases of the aforesaid kind are efficiently purified from gaseous mercury.
• This object is achieved by a method having the characterizing features in that the gas, at a temperature between 350° Kelvin and 550° Kelvin, is caused to contact a solid sorbent, preferably in a fluidized bed, the sorbent consisting of powdered calcium hydroxide and of reaction products from the reaction between calcium hydroxide and gaseous hydrogen chloride, whereafter the sorbent is separated in a dust separator.
• a partial gas stream of the flue gases from a refuse incinerator was introduced.
• hydrated technical lime was batched in an amount of between 3 and 0,5 g per cubic meter flue gas, which contained about 200 ⁇ g gaseous mercury per cubic meter flue gas.
• Other pollutions in the flue gas were a.o. hydrogen chloride and sulphur dioxide.
• the gas had a temperature of between 250° C. and 150° C. and was passed through the gas purification equipment. When the mercury content was measured at the outlet from the dust separator, it was found that the gaseous mercury content had decreased to about 5 ⁇ g gaseous mercury per cubic meter flue gas.

Landscapes

• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Analytical Chemistry (AREA)
• General Chemical & Material Sciences (AREA)
• Oil, Petroleum & Natural Gas (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Health & Medical Sciences (AREA)
• Biomedical Technology (AREA)
• Environmental & Geological Engineering (AREA)
• Dispersion Chemistry (AREA)
• Treating Waste Gases (AREA)
• Solid-Sorbent Or Filter-Aiding Compositions (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=20336984

Family Applications (1)

Country Status (9)

Cited By (19)

Families Citing this family (1)

Citations (8)

• 1979
  • 1979-01-10 SE SE7900209A patent/SE415448B/sv not_active IP Right Cessation
• 1980
  • 1980-01-04 FI FI800032A patent/FI64748C/fi not_active IP Right Cessation
  • 1980-01-07 JP JP48280A patent/JPS5594627A/ja active Pending
  • 1980-01-08 EP EP80100082A patent/EP0013567B1/en not_active Expired
  • 1980-01-08 AT AT80100082T patent/ATE1219T1/de not_active IP Right Cessation
  • 1980-01-08 DE DE8080100082T patent/DE3060557D1/de not_active Expired
  • 1980-01-09 NO NO800049A patent/NO148910C/no unknown
  • 1980-01-09 CA CA000343313A patent/CA1141523A/en not_active Expired
  • 1980-01-10 US US06/111,126 patent/US4274842A/en not_active Expired - Lifetime

Patent Citations (8)

Non-Patent Citations (1)

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